Various transmission assemblies, such as those used in the drivetrains of various work vehicles, may include transmissions that incorporate “synchronizers” that facilitate the selective coupling of a rotating drive shaft (e.g., powered by an engine or drive motor) with one or more range gears. Often, the synchronizers are actuated by a shift fork that rides along a shift rail to move a shift collar splined to the drive shaft into meshing engagement with a gear to transmit rotational power from the drive shaft to the gear, and thereby initiate or effect a change in range speed and torque to the wheels or tracks of the work vehicle. Reversing actuation of the shift fork disengages the shift collar from the gear, and thus the transmission from the drive shaft until another gear is engaged. The shift fork may be actuated manually or under power (e.g., via hydraulic power). In some cases, the shift fork may be eliminated and the shift collar may be engaged with the gear by a hydraulic piston arrangement and disengaged by other mechanical means (e.g., return springs).